1. Technical Field
The present invention relates to a circuit board and a heat dissipation device thereof.
2. Related Art
With the continuous development of technologies, the present consumer electronic products have a more and more intensive process due to an increasingly growing working clock of processing chips (CPU/Scalar). Processing chip power is becoming increasingly higher; accordingly, heat generated by the processing chips may be accumulated, resulting in internal elements being damaged, or working efficiency being reduced. In the prior art, heat dissipation devices are additionally disposed on processing chips, and the heat accumulation problem of the processing chips is resolved using the heat dissipation devices.
However, during operation a chip generates signals unexpected by a system or even signals adversely affecting the operation, and an adjacent heat dissipation device receives a high-frequency noise generated by the chip. However, because of the disposition of the heat dissipation device, especially a heat dissipation fin, which is not conductively connected to a circuit board where the chip is located, the high-frequency noise generated by the chip is coupled to the heat dissipation fin and has no path for elimination. Consequently, in a wireless transmission manner, the high-frequency noise radiates out by using the heat dissipation fin as an antenna. As a result, adjacent electronic elements are subject to interference of the high-frequency noise, resulting in that the system is unstable or has unexpected problems.
Therefore, high heat-accumulation caused due to the high-clock operation of the processing chips may be resolved by disposing the heat dissipation devices. However, after the heat dissipation devices are disposed, the high-frequency nose generated due to the high-clock operation of the chips is radiated to a surrounding environment by using the heat dissipation devices as antennas, and an electromagnetic interference problem arises spontaneously.
In conclusion, the circuit boards and the heat dissipation devices thereof in the prior art have an electromagnetic interference problem resulting from that high-frequency noise generated during a high-speed operation of chips, radiates out through heat dissipation elements.